The stems are used to replace your existing stem on your C-Clamp or Pedestal Base. There are 2 sizes available. X8029 7" Alum. stem and a X8030 9" Alum. stems. These stems fit only Tube or Traveler Series Vises. We do not recommend using the Alum. stem on a standard, saltwater or Deluxe Saltwater Base stem support. X8054 7" Stainless Steel Stem for Traveler Series and Tube Fly Vises This versatile stem allows the use of Traveler and Tube Series Vises on the Lap Extension, the Standard, Saltwater and Deluxe Saltwater Base.